Electrical resistor



Aug. 4, 1943. H. M. HUCKE 2,327,793

ELECTRICAL RESISTOR Original Filed May 10,1940

IIIIJ'IIIIIIIIA .IIIIIIIIIIIIII flaw mgg Patented Aug. 24, 1943 ELEO'I'RIGAL RESISTOR Herbert M. Hucke, Haddonfleld, N. 1., assignor to United Air Lines Corporation, (7111- Transport cago, BL, a corporation of Delaware Original application May 10, 1940, Serial No.

334,419. Divided and this application November 24, 1M1, Serial No. 420,167

' 7 Claims. (cl. can-i) This application is a division of my co-pending application Ser. No. 334,419, filed May 10, 1940 (Patent No. 2,311,608, granted February 16, 1943) This invention relates to electrical resistors and has particular relation to flexible resistors having predetermined desired electrical and mechanical characteristics.

It has been found that for certain uses it is desirable to provide'a flexible resistor of substantially cylindrical form and relatively large diameter and high resistance as compared with ordi-' nary resistance wire or the like, which can be made in continuous lengths, may be provided with an insulating covering, and may be coiled up and uncoiled or otherwise flexed as desired.

The application of such a resistor to one par- I ticular use is set forth in my aforesaid co-pending application, having reference to a static discharge device which may be used on aircraft. In a system of the character referred to in that application, this type of resistor is utilized as one of the component parts of a composite electrical conductor which may be projected from an aircraft in flight to extend in trailing relation thereto for the purpose of discharging static electrical charges in a desired manner. The relatively large diameter of the resistor prevents corona discharge therefrom, while its relatively high resistance serves to damp oscillatory currents in the discharge circuit. The properties and characteristics of such a resistor also make it applicable to other uses.

The primary object of the present invention is to provide a resistor having the qualities of flexibility and relatively large diameter and high resistance as aboveindicated.

It is a further object of the invention to pro vide a resistor of the above-indicated character which shall be of substantially uniform electrical resistivity throughout and shall retain this characteristic permanently.

A further object of the invention is to provide such a resistor with an effective insulating and protective covering to render the resistance element impervious to moisture and other external effects without impairing the flexibility or other desired characteristics of the construction.

A further object is to provide a resistorv of the above-indicated character which shall have highv mechanical strength and durability and shall be economical to manufacture and convenient to handle.

This invention achieves the foregoing and other objects and advantages which will be apparent having a body of substantially nonconducting rope-like material, such as jute, hemp, or the like, impregnated with a conducting material such as colloidal graphite. A flexible waterproof covering of rubber or other suitable material is applied to the rope-like body after impregnation thereof, and this construction is made in any desired lengths which may be coiled up for use or storage or handled in any other convenient manner.

A preferred embodiment of the invention is illustrated in the accompanying drawing forming a part hereof, in which Fig. 1 is a view partly in elevation and partly in longitudinal section of a fragmentary length of a. resistor made in accordance with the invention, and

Fig. 2 is a transverse sectional view of the same.

Referring to the drawing, the resistor comprises a body ll of fibrous, flexible, rope-like material, such as Jute, hemp, or the like, impregnated with colloidal graphite, which may be derived from an aqueous graphite dispersion such as is commercially available under the name "aquadag." It will be understood, of course, that after the rope-like body, has been impregnated to the desired extent, it will be dried and the graphite will-then be left deposited in extremely minute particles uniformly distributed throughout the flbers of the body and the interstices therein, thus converting the body into an electrical resistance element of definite, relatively high resistivity. These graphite particles may be referred to for convenience as being in granular form, but it is not to be inferred from this that they areof more than minute size.

Over the impregnated body H is placed, by

extrusion, molding, or any other suitable process,

a watertight insulating covering ii of rubber or other suitable material. This covering renders the resistor impervious to moisture and other external influenceswhich might have detrimental sistance element H by terminal members such as rope-like body ll may be on the order of three- I 3, or by any other suitable means. I As an illustrative example, the diameter of the sixteenths 'ofan inch, but it will be understood that it maybe made many desired size, dependto those skilled in the art by providing a resistor 65 ing upon the electrical and mechanical characteristics desired. The electrical resistivity oi? the body it also depends upon the process of treatment thereof and the resulting character and extent of impregnation by the graphite. Eowever, a suitably processed resistor of the size mentioned by way of example above may have a resistance construction including the protective covering has a high degree of flexibility, mechanical strength and durability, and the material may be produced in any desired lengths to be applied to various useful purposes. 7

While only one specific embodiment of the invention has been illustrated and described herein, it will be apparent to thoee'skilled in the art that various changes and modifications may be made in the details of construction and the process of manufacture without departing from the spirit and scope of the invention as set forth in the appended claims.

What isclaimed as new and is desired to secure by Letters Patent is:

1. An electrical resistor having a body of jute, granular graphite distributed throughout its length and carried by said jute, and avflem'ble rubber covering encompassing said jute. and granular graphite and extending throughout the length of said resistor.

2. An electrical resistor comprising a fibrous rope body oijute, hemp, or the like having interstices, granular resistance material carried by said rope within said interstices and a waterasa'mos proof, flexible material covering said fibrous rope and confining said granular resistance materi within the interstices of said rope.

3. As an article of manufacture, an electrical resistor consisting a. rope-like fibrous body of jute, hem-p. or the 1ike,lhaving interstices, a

, body of fibrous strands 01' nonconducting mateliquid-borne granular resistahce material substantially uniformly distributed throughout said rope-like fibrous body, and a. waterproohflexible rial, colloidal graphite distributed in minute particles throughout; said body by impregnation oi the latter with an aqueous dispersion of such graphite, and a flexible, waterproof covering surrounding saidbody.

6. An electrical resistor comprising a rope-like body of jute strands, colloidal graphite distributed in minute particles throughout said body by impregnation oi the latter with an aqueous dispersion of such graphite, and a flexible, waterproof covering surrounding said body.

7. An electrical resistor of relatively large diameter and high resistance as compared with resistance wire, comprising a rope-like body of fibrous strands of nonconducting material, colloidal graphite distributed along and carried by said body, and a flexible, waterproof covering surrounding said body.

' HERBERT M. HUCKE. 

